Malicious PDF — malware analysis report

Static analysis result for SHA-256 50555373c82cb81c…

MALICIOUS

PDF

70.4 KB Created: 2021-09-25 17:00:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9eb97fc7b4b44e01d91491e184b2ba47 SHA-1: 3a9e3ac527453b25eb751c6a0c5ec66f0317b8a0 SHA-256: 50555373c82cb81c3adce539133bf451e669a82172c4b5a39adda95b4577c788
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, potentially leveraging embedded JavaScript for exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://allytemp.ru/uplcv?utm_term=ridmik+keyboard+app PDF link annotation
    • https://mklaassen.nl/images/file/64620787353.pdfIn PDF document text
    • http://challendor.com/fckeditor/upload/file/86872363924.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/f50b69f6bf676e6e3bcad89835524079/95733657844.pdfIn PDF document text
    • https://pt2-turbo-j3t.com/contents/files/potefomilakeses.pdfIn PDF document text
    • http://ip-malkov.ru/uploads/files/69743206324.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/jamekegabosatewar.pdfIn PDF document text
    • https://ferest.ro/imagini_ws/kijezomu.pdfIn PDF document text
    • http://crocepadrekolbe.it/userfiles/files/55065639172.pdfIn PDF document text
    • http://kaus21.com/userData/board/file/solotosesipumow.pdfIn PDF document text
    • http://bielle-srl.com/userfiles/files/zosif.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/jejomobetowijufuwi.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/k272agjtcusi1o5mo0a54m8qfa/totosuwusunofakevonuf.pdfIn PDF document text
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/nu4s9vetm6l1gsgefrggo0bph4/nusejasasusixadixejatipaz.pdfIn PDF document text
    • http://occahomesearch.com/userfiles/files/zuzizefizupama.pdfIn PDF document text
    • http://3e-machinery.ru/app/webroot/filesfiles/kasosavogudolugad.pdfIn PDF document text
    • http://bmfjhjk.friend-match.com/upload/files/linewebunigajebowajujef.pdfIn PDF document text
    • https://koparieshorvathbusz.hu/files/file/42511719503.pdfIn PDF document text
    • http://clingac.com/d/files/71447994293.pdfIn PDF document text
    • http://xn----7sbezcba9a5aggb3j.xn--p1ai/ckfinder/userfiles/files/xunekiminerafibifugu.pdfIn PDF document text
    • http://k1a.ru/images/files/file/87456609087.pdfIn PDF document text
    • http://aktifbant.com/resimler/files/vudozewiregade.pdfIn PDF document text
    • http://gndpta.eu/news_objects/files/51848631913.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/wutilinumugubemekewi.pdfIn PDF document text
    • https://cytokin.ca/upload/editor/file/zogafozirefupigasewamuwa.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b239.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB239 10528 bytes
SHA-256: b0eac8d22223eff2140c3a09b45ea50926e04c501ae10f2cbcb19aa2de257c48
font_01_sfnt_off0000c9f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9F0 16556 bytes
SHA-256: f294fc1f3ddaaec56fe7fc1e3cbb315e023144dcf9918e0bac2bebf8d4c2f195
font_02_sfnt_off0000f415.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF415 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1